feat: Enhance entity options retrieval with additional fields support

- Updated the `getEntityOptions` function to accept an optional `fields` parameter, allowing clients to specify additional columns to be retrieved.
- Implemented logic to dynamically include extra columns in the SQL query based on the provided `fields`, improving flexibility in data retrieval.
- Enhanced the response to indicate whether extra fields were included, facilitating better client-side handling of the data.
- Added logging for authentication failures in the `AuthGuard` component to improve debugging and user experience.
- Integrated auto-fill functionality in the `V2Select` component to automatically populate fields based on selected entity references, enhancing user interaction.
- Updated the `ItemSearchModal` to support multi-selection of items, improving usability in item management scenarios.

frontend/components/auth/AuthGuard.tsx

@@ -3,6 +3,7 @@
 import { useEffect, ReactNode } from "react";
 import { useRouter } from "next/navigation";
 import { useAuth } from "@/hooks/useAuth";
+import { AuthLogger } from "@/lib/authLogger";
 import { Loader2 } from "lucide-react";
 
 interface AuthGuardProps {
@@ -41,11 +42,13 @@ export function AuthGuard({
     }
 
     if (requireAuth && !isLoggedIn) {
+      AuthLogger.log("AUTH_GUARD_BLOCK", `인증 필요하지만 비로그인 상태 → ${redirectTo} 리다이렉트`);
       router.push(redirectTo);
       return;
     }
 
     if (requireAdmin && !isAdmin) {
+      AuthLogger.log("AUTH_GUARD_BLOCK", `관리자 권한 필요하지만 일반 사용자 → ${redirectTo} 리다이렉트`);
       router.push(redirectTo);
       return;
     }